pettsir

i can't see down by the distributer too well, all i see is a blue light coming from the front of the engine, by the coil, and where the plugs are. at the plugs i don't see arcing, and at the coil it doesn't appear to be arcing just a blue glow. but i can't tell by the distributer. the engine seems to be running pretty well. i would imagine if i had all that crossfiring i would feel it. as far as running too rich or lean, all the plugs are burning identically, and all well. i have'nt done a leak down test yet, just compression, and they were all about the same, no one cylinder stuck out. it doesn't look rich, or lean, or lacking in compression. if the new wires don't cure it then i will do a leakdown test and go through it one wire at a time.

SunCr

Really don't think you have an ignition or a compression problem (unless there's a burnt valve). Looking at your mods, you've added addt'l air and the means to get it out, but done nothing for fuel. That makes conditions ripe for a lean mixture which leads to high combustion temps and if there's any restrictions to fuel flow, a lean miss. You may not feel it, but you did say there was a loping idle. The computer isn't looking for what you can feel anyway - just poor emissions. If the situation didn't exist before the mods, then suspect something about the modifications you've made (especially if they didn't exist before you made them) along with something else and if the ignition checks out, it's probably fuel related, or maybe a vacuum or header leak.

TravisD

Soon after I bought my LT4 in 2001 I started having problems that were similar. It took the dealer 3 tries to get a PCM that worked.